Thermal regulatory responses to submaximal cycling following lower-body cooling in humans

This study compared the effects of pre-exercise cooling with control water immersions on exercise-induced thermal loads derived from steady-state submaximal exercise. Eight healthy male participants [mean (SEM) age 29 (1) years, maximal oxygen uptake 3.81 (0.74) l·min^–1, and body surface area 1.85 (0.11) m²] took part in experiments that included 30 min of baseline data collection [ambient temperature 21.3 (0.2°C)], 30 min of immersion in water to the level of the supra-iliac crest [water temperatures of 35.1 (0.3)°C for thermoneutral and 17.7 (0.5)°C for precooled treatments], and 60 min of cycling exercise at 60% of maximal oxygen uptake. No significant differences were noted during exercise in net mechanical efficiency, metabolic rate, O₂ pulse, or ratings of perceived exertion between the two treatments. Precooling resulted in a significant negative body heat storage during immersion and allowed greater heat storage during exercise. However, net body heat storage for the entire protocol was no different between treatments. Cooling significantly lowered rectal, mean skin, and mean body temperatures as well as more than doubling the exercise time until a 0.5°C rectal temperature increase was observed. The cooling trial significantly delayed onset of sweating by 19.62 min and decreased sweat rate by 255 ml·h^–1 compared to control. Thermal and sweat sensation scores were lower after the cooling treatment compared to control. These data suggest that lower-body precooling is effective at decreasing body heat storage prior to exercise and decreases reliance on heat dissipation mechanisms during exercise. Therefore, this unique, well-tolerated cooling treatment should have a broader application than other precooling treatments. Electronic Publication     

Defensin deficiency, intestinal microbes, and the clinical phenotypes of Crohn's disease

Crohn's disease is a chronic, inflammatory disease of the intestinal mucosa. Although intestinal bacteria are implicated in disease pathogenesis, the etiology is still unclear. The main location of disease is the small intestine (ileum) and the colon. Ileal disease has been linked to a mutation in the NOD2 gene. Defensins are antimicrobial peptides and in the ileum, are mainly expressed in Paneth cells, epithelial cells that also express NOD2. In the colon, defensins are expressed by enterocytes or metaplastic Paneth cells. Crohn's disease patients with ileal involvement, compared with controls or Crohn's patients without ileal involvement, have diminished expression of ileal Paneth cell defensins. This decrease is even more pronounced in Crohn's patients displaying a NOD2 mutation. In contrast, Crohn's disease of the colon is characterized by an impaired induction of beta-defensins in enterocytes. The colonic expression of the constitutive beta-defensin 1 is also decreased in the inflamed colonic mucosa, but this decrease is less specific to Crohn's disease, as it can also be found in ulcerative colitis patients. In conclusion, the regional localizations of Crohn's disease, ileal or colonic disease, can be linked to different defensin profiles. Crohn's disease of the ileum is associated with diminished defensin expression in Paneth cells. Crohn's disease of the colon is associated with diminished beta-defensin expression in enterocytes. Thus, it can be speculated that decreased defensin levels lead to a weakened intestinal barrier function to intestinal microbes and might be crucial in the pathophysiology of Crohn's disease.     

Beitrag zur Methodik der Bestimmung des „Leicht Abspaltbaren“ Eisens im Serum und Einige Klinische Ergebnisse

Zusammenfassung Es wird in Kürze der Stand des Untersuchungsverfahrens bei der Erforschung des leicht abspaltbaren Eisens im Serum besprochen, sowie die ungeklärte und schwierige Lage der klinischen Bearbeitung dieses Gebietes im allgemeinen dargelegt. Es folgt eine Schilderung der bei der eigenen Arbeit verwandten Barkanschen Methode und der mit ihr gemachten Erfahrungen.Aus der Darstellung der Ergebnisse und den Tabellen am Schluß, die einen Überblick über Untersuchungsweise und klinische Befunde der verschiedenen Untersucher bieten sollen, geht ein widerspruchsvolles Bild hervor, aus dem auch auf die Schwierigkeit und teilweise Unzuverlässigkeit der Methoden geschlossen werden darf. Die hohe Fehlergrenze, die ich mit der Barkanschen Methode hatte, zeigt dasselbe.Im übrigen darf man wohl aus den Zusammenstellungen folgern, daß zwischen dem Serumeisen und dem Blutfarbstoff kein unmittelbarer Zusammenhang besteht, ein Schluß, zu dem sowohl Kliniker, wie Chemiker auch im einzelnen schon gekommen sind, der jedoch nicht unwidersprochen ist.Herrn Prof.Schottmüller danke ich für die Überlassung des erforderlichen Materials an seiner Klinik, Herrn Prof.Schumm für die freundliche Überlassung eines Arbeitsplatzes und seine liebenswürdige Unterstützung meiner Arbeit, sowie Fräulein Dr.Mertens und den Herren Dr.Budelmann und Dr.Dohmen für ihre freundliche Hilfsbereitschaft.     

A deletion–insertion mutation in the phosphomannomutase 2 gene in an African American patient with congenital disorders of glycosylation‐Ia

Congenital disorders of glycosylation (CDG) are a group of metabolic disorders with multisystemic involvement characterized by abnormalities in the synthesis of N‐linked oligosaccharides. The most common form, CDG‐Ia, resulting from mutations in the gene encoding the enzyme phosphomannomutase (PMM2), manifests with severe abnormalities in psychomotor development, dysmorphic features and visceral involvement. While this disorder is panethnic, we present the first cases of CDG‐Ia identified in an African American family with two affected sisters. The proband had failure to thrive in infancy, hypotonia, ataxia, cerebellar hypoplasia and developmental delay. On examination, she also exhibited strabismus, inverted nipples and an atypical perineal fat distribution, all features characteristic of CDG‐Ia. Direct sequencing demonstrated that the patient had a unique genotype, T237M/c.565‐571 delAGAGAT insGTGGATTTCC. The novel deletion–insertion mutation, which was confirmed by subcloning and sequencing of each allele, introduces a stop codon 11 amino acids downstream from the site of the deletion. The presence of this deletion–insertion mutation at cDNA position 565 suggests that this site in the PMM2 gene may be a hotspot for chromosomal breakage. Published 2002 Wiley‐Liss, Inc.     

The direct early diagnosis of cystic fibrosis by the detection of the deltaF508 CFTR gene mutation in a prematurely delivered boy

The suspicion of prenatal meconium ileus syndrome was raised in a pregnancy in a family with no history of cystic fibrosis because of significantly higher maternal serum alpha-fetoprotein in the 16th and 19th week of gestation, dispersed areas with increased echogenity in the fetal abdomen, slight fetal ascites in the 24th-25th weeks of gestation, decreased amniotic fluid gamma-glutamyltranspeptidase (GGT) activity and alpha-fetoprotein level in the 25th-26th weeks, and normal 46,XY karotype of the fetus. The detection of a homozygous deltaF508 cystic fibrosis transmembrane regulator (CFTR) gene mutation, by means of PCR from a small amount of white blood cells and urine sediment cells, substantiated the diagnosis of cystic fibrosis in a prematurely delivered boy in the 28th week of gestation. The repeated sweat test was unsuccessful. The autopsy examination confirmed the diagnosis of cystic fibrosis. Fetal meconium ileus syndrome was complicated by peritonitis and by formation of a meconium pseudocyst. Direct PCR typing improves postnatal diagnostic possibilities in the early neonatal period in prematurely delivered babies when the sweat test is difficult to perform.     

Synectin/syndecan-4 regulate coronary arteriolar growth during development.

Syndecan-4 and its cytoplasmic binding partner, synectin, are known to play a role in FGF-2 signaling and vascular growth. To determine their roles in coronary artery/arteriolar formation and growth, we compared syndecan-4 and synectin null mice with their wild-type counterparts. Image analysis of arterioles visualized by smooth muscle alpha-actin immunostaining revealed that synectin (-/-) mice had lower arteriolar length and volume densities than wild-type mice. As shown by electron microscopic analysis, arterioles from the two did not differ in morphology, including their endothelial cell junctions, and the organization and distribution of smooth muscle. Using micro-computer tomography, we found that the size and branching patterns of coronary arteries (diameters > 50 microm) were similar for the two groups, a finding that indicates that the growth of arteries is not influenced by a loss of synectin. Syndecan-4 null male mice also had lower arteriolar length densities than their gender wild-type controls. However, female syndecan-4 null mice were characterized by higher arteriolar length and volume densities than their gender-matched wild-type controls. Thus, we conclude that both synectin and syndecan-4 play a role in arteriolar development, a finding that is consistent with previous evidence that FGF-2 plays a role in coronary arterial growth. Moreover, our data reveal that gender influences the arteriolar growth response to syndecan-4 but not to synectin.     

Lamina propria plasma cells in inflammatory bowel disease: intracellular detection of immunoglobulins using flow cytometry

This is the first application of flow cytometry for the detection of lamina propria plasma cells and their intracellular immunoglobulins in patients with inflammatory bowel disease compared to healthy controls. The study has been focused on the distribution of IgA, IgG, IgM and the four IgG subclasses. Plasma cells were detected as high CD38 positive cells. For fixation and permeabilisation a single step reagent, Ortho Permeafix®, was used.

By flow cytometry, in patients with inflammatory bowel disease compared to healthy controls, a higher percentage of IgG⁺ cells can be observed, in Crohn's disease also a higher percentage of IgM⁺ cells. Regarding the IgG subclass distribution, patients with Crohn's disease show an increase in IgG2⁺ cells, patients with ulcerative colitis an increase in IgG1⁺ and IgG3⁺ cells. These results do agree with and expand the results of earlier immunohistochemical and functional studies, which are favoured today. For the determination of lymphocyte subset proportions and the detection of intracellular antigens, flow cytometry provides a useful alternative to well-established immunohistochemical methods. By analysing a larger number of cells, this method is more reproducible and less prone to interobserver variations than immunohistochemistry, which needs the pre-selection of a mucosal area, the microscopic scoring of a limited number of cells and the circumvention of high background staining. The optimized flow cytometric protocol used in this study might be a promising tool for further investigations of various purposes.     

Are Anti-Beta2-Glycoprotein-I Antibodies Markers for Recurrent Pregnancy Loss in Lupus Anticoagulant/Anticardiolipin Seronegative Women?

Problem  Anti-beta₂-Glicoprotein-1 antibodies (anti-β₂GPI-ab) have been related to recurrent miscarriage (RM) with conflicting results. The aim was to evaluate the role of anti-β₂-GPI-ab as unique biological marker in RM related to antiphospholipid (aPL).
Method of study  A cohort study that included 59 cases, divided in two groups, was designed: group 1 comprised 43 pregnant women with 'obstetric' antiphospholipid syndrome (APS) and group 2 included 16 cases with similar complaints but only having repeatedly anti-β₂-GPI-ab. Previous thrombosis and/or inherited thrombophilia were excluded. Lupus anticoagulant, anticardiolipin antibodies (aCA), anti-β₂-GPI-ab, and other autoantibodies were analyzed. Miscarriages, premature births, pre-eclampsia, live births, placental and systemic thromboses were studied.
Results  No differences in previous obstetric complications were detected ( P  =   1.00–0.164). After the treatment, differences in number of obstetric complications were not seen ( P  =   1.00). Live births were similar in two groups (88.4% and 93.7%; P  =   1.00). Placental thrombosis was equal in both groups, 93.3% versus 80% ( P  =   1.00).
Conclusion  These results suggest that anti-β₂-GPI-ab may be considered a biological marker for obstetric APS.